#1 

Set goals! Set both long and short-range goals to keep yourself motivated. Be sure that the short-range goals will eventually lead you to your big-picture, long-range ones. Consider them stepping stones on the path towards something bigger.

#2

Do what you like to do. Don't just start doing something because everyone else is; find what you truly enjoy and do that. In the end, if you don't have a genuine interest in your workouts and lifestyle, you're going to hinder your progress.

#3

Switch things up! I know this may sound kind of funny after just reading #2, but as humans, we can get bored of doing the same thing over and over. As well, our muscles can get "bored" and we can plateau. Do not be afraid to try new things and incorporate change to keep you entertained and your muscles guessing!